Apparatus for temperature control



March 5, 1940.

c. A. SCHAEFER APPARATUS FOR TEMPERATURE CONTROL ori inal Filed May 22, 1956 '7 Sheets-Sheet 1 R 2 FIG. 2.

llulll INVEN TOR. CARL FLSCHAEFER,

TTORNEYS.

March 5, 1940. Q SCHAEFER 2,192,276

APPARATUS FOR' TEMPERATURE CONTROL Original Filed May 22, 1936 7 Sheets-.-Sheet 2 INVENTOR. cnRL A. SCHAEFER,

.- A TTORNEYS.

March 5, 1940.

1 Filed ma 22, 1936 7 Sheets-Sheet 3 Origiha X 0 mm hm NN\ v q 4 4 4 000 0000 v00 n 0 0 0 o m INVENTOR. CARL A-SCHAEFER,

w a E ATTORNEYS.

March 5, 1940. c. A. SCHAEFER APPARATUS FOR TEMPERATURE CONTROL 7 Sheets-Sheet 4 Original Filed May 22, 1956 ko nw III kUvRzQU EQtSQU IN V EN TOR CARL A .SCHAEFER.

ATTORNEYS.

Marc 532 1940. Y c. A. SCHAEFER 2,192,276

APPARATUS FOR TEMPERATURE CONTROL Origi nal Filed May 22, 1936 7 Sheets-Sheet 5 44 INVEN TOR.

CARL A. 6OHAEFER,

A TTORNEYS.

March 5, 1940. c. A. "SCHAEFER 2,192,276

APPARATUS FOR TEMPERATURE CONTROL Original Filed ma 22, 1936 7 Sheets-sheet s 0 5000 ,g r iO OC OO O OOCD 0 0 2000000:( r :0 O 'O( DOOOOOG) O O :OO O O O K EC) .0 OC" DOOOOOCD O Q iO O O OO OK 0 0 O Y I /2/ '1 1, O H 1 I29 127,] J 1i CARL A S C k262i??? 12a BY 7 O A TTORNEYS.

C. A. SCHAEFER APPARATUS FOR TEMPERATURE CONTROL March 5, 1940.

Origina 1 Filed May 22, 1936 7 Sheets-Sheet 7' v Q 4 C Q 00000000 00000 000 0 0 0 0 0 0 0 0 0 0 v 0 N 0 0 00 0 0 0 0 0 0 W "UN 9 I .mm Y T E M m V 0 M n Patented Mar. 5, 1940 UNITED STATES- APPARATUS FOR COOL Carl A. Schaefer, Detroit, ,Mich. Original application May 22, 1936, Serial No.

81,160. Divided and this application lllecembet 5, 1936, Serial No. 114,415

This inventionrelates to means for maintaining a. uniform condition and more particularly to means for maintaining a uniform temperature, one application of which may be in an incubator and separate hatcher for eggs and in this latter respect the invention constitutes an improvement over the method and meansv set forth in U. S.

Letters Patent 1,968,355 issued July 31, 193d, on an application filed by me.

One object of the invention is a method which .comprises controlling the temperature of an incubator or the like by the application of artificial heat or of cooling air or other cooling medium as required, by a single thermostatic means.

Another object of the invention is a method of operating an incubator and a. hatcher by placing eggs in the incubator, controlling the temperature therein by supplying artificial heat and admitting outside air as needed, controlling the supply of artificial heat and the admission of outside air therein by a single thermostatic means,

moving the eggs to a hatcher from the.

ing means and an element movable in response to temperature for selecting one of said means for operation and for controlling the selected means. H Another object of the invention is a thermo- 40 .static control system involving a contact element movable in r sp nse to temperature and cooperating with spaced contacts corresponding to opposite extreme temperature conditions to select either heating meansor cooling means for opera- 4; jtion as required byv the-temperature condition and cooperating with at leastone contact element corresponding to the-temperature condition desired,

60; Other objects and features of the invention will be readily'apparentto those skilled in theert from the following specification and the accompanying drawings embodiments of the invention. application I is a: division otmy appllcttlon Serial N0. 81,'100,

to control the'applicationrot aselected (or. zoo-o) filed May 22, 1936, and reference is herein, also, made to copendingapplication Serial No. llel filed December 5, 1936, also a division of applicatlon Serial No. 81,160 and in which is claimed a method of temperature control herein described 5 and illustrated.

Fig. 1 is a. partial front elevatiompartly in transverse section, of an incubator or hatcher.

Fig. 2 is a fragmentary horizontal section on the line 2-2 of Fig. 1. I it Figs. 3, 4, 5, and 6 are electrical wiring diagrams in different stages of operation, showing the manner of controlling the temperature conditions by electrically operated means.

Fig. 7 is an enlarged longitudinal section on 35 the line '!--'-'i of Fig. 1.

V Fig. 8 is a horizontal section on the line 8-3 of Fig. 7.

Fig. 9 is a vertical section on the linest of Fig. 10 isan elevation of the thermostat, there being one in the incubator andone in the hatch- Fig. 11 is a diagrammatic view showing the operating ranges of the thermostat in the incu bator and hatcher for controlling the heater and the air supply.

Fig. '12 is an enlarged fragmentary longitudinal section" of some of the details or the-mechahim as seen on the line l2 l2 of-Fig. 2. 3

Fig. 13 is a fragmentary transverse section on the line l3-l3 of Fig. 12.

Fig. 14 is a view similar to Flg.'12, but with the parts in a different working position.

Fig. 15 is an enlarged fragmentary transverse section on the line l5-l5 of Fig. 12.

Fig. 16 is a view of the thermostat and the leads connected thereto, with a portion of the casing enclosing the thermostat broken away.

' Fig. 17 is a side elevation of the casing enclosing the thermostat partly broken away and of the supporting bracket for the casing. I

- Fig. 18 is a horizontal section on the line ll-IS of Fig. 16. I

Fig. 19 ls-a heat chart showing. the heafi. Produced by the eggs as the incubation and hatch ing thereof advances. r 7

Fig. 20 is a'vlew of the hatcher similar to Fig. 8, the'latter being a view of the incubator. I

{The incubator andhatcher areconstructedalikc as to the heater and air damperfm-and as to the-thermostat for controlling the supplying of artificial heat and the admission of outside air. Fig. 8 shows a horizontal-section o! the-incubotor and Fig. 20 showsa similar vlewof the admit outside air to cool the air therein, and at hatcher. Similar reference numerals will be applied to like parts of the incubator and the hatcher. I will, "therefore, describe the parts of the incubator only.

In the drawings, the front wall of the casing.

of the incubator is numbered I, the rear wall 2,

. the side walls 3, the top" and the. bottom or floor is numbered-5. An inside ceiling 6 is also employed to provide for heat insulation, while in the side and rear walls and in the floor a central sheet of insulating fiber is used for the same purpose.

Figs. 1, 7 and 9 show the egg trays I, having the usual mesh bottoms. These egg trays are arranged in two tiers, one on eachside, with a central corridor 8 between them. Doors 9 are provided to permit access to the spaces in which the egg trays are stacked, while the corridor 8 is accessible through the door l0.

Air is circulated over and through the egg trays preferably by an electric fan It, supported in a vertical partition l2 at the rear of the corridor 8. This partition is spaced a short distance from the rear wall 2 and has the opening l3 through which passes the air from the fan, the fan being so mounted that the direction of circulation of air is toward the rear wall 2 from the corridor 8. The air currents from the fan divide and spread in all directions first entering the passages I3, and then entering the passages M, as seen in Fig. 8. The air then passes from the passages M over and through the egg trays and returns to the corridor 8 and the fan H. Preferably the air passes horizontally between the egg trays 'l, but the present invention is not confined to this horizontal movement of the air, as the passageways could be arranged to direct the air so that it would pass vertically through the egg trays..

When the air is passed horizontally between the egg trays, division plates 1 support the egg trays l and prevent vertical movement of the. air through the tiers of egg trays. The arrows in Fig. 8 indicate the horizontal path of the air.

electric current from a common source the supply' to the heating element being under the control of the thermostat i8, which actuates the switches 18*, [8, 88, l8 38 These switches are contacts, preferably of the mercury tube type, magnetically actuated by coils 9B and 9% and their respective armatures.

The thermostat is is located in the corridor 3 and will be described more in detail later. In the embodiment of .the incubator illustrated in my Patent 1,968,355, it wasnecessary to employ two thermostats for the incubator or hatcher, whereas with the present invention it is necessary to employ but one thermostat in the incubator or hatcher. The thermostat i8 is preferably located in the corridor 8 and controls the position of the switches lB l8", I8", I8 I8 which control the supply of artificial heat and i the admission of outside air.

During the operation 'of the incubator and .heat' at times and at other times it is necessary'to other times it is necessary to cut 011 the supply of artificial heat without admitting outside air, in order to maintain the temperature of the air within the desired range.

When the eggs are placed in the incubator, they are cool and do not giveofi any heat. At that time it is necessary to supply artificial heat.

As the process of incubation progresses the eggs I develop heat and as soon as this heat from the eggs raises the temperature of the air above the desired maximum, it is necessary to cut 011? the supply of artificial heat. If the temperature of the air continues to rise and reaches a predetermined point, it is necessary to admit cooling air from the outside to reduce the temperature.

When the eggs are removed from the incubator, shown in Figs. 1, 7, 8 and 9, for transfer to the hatcher, which is usually done at the end of seventeen or seventeenv and one-half days, although it can be done at other times, the eggs are developing considerable animal heat, but in transferring them to the hatcher, shown in Fig. 20, they are cooled. It is then necessary to supply artificial heat in the hatcher to restore the eggs to the desired temperature, when the artificial heat is out oh and cooling air admitted as;

needed to maintain the eggs at the proper temperature. When outside air is admitted to the incubator and to the hatcher, some of the air therein is permitted to escape so that the outside air can enter.

Fig. 19 shows a heat graph which illustrates the heat developed by the eggs as the incubation and hatching progresses. A period of twentyone days is illustrated, which is the customary period for incubating and hatching chicken eggs.

The curved line indicates the heat units given ofi per egg per day. This is shown in calories (252 calories equal one B. t. u.) The numerals at the right of Fig. 19 indicate the days, while the numerals at the'top of Fig. 19 indicate the calories of heat.

During the first four days the eggs give oh no heat, but they absorb some heat during that period. After the fourth day, the eggs give ofi heat, which steadily increases until about the eighteenth day, when there is no increase for about a day. Then the increase in heat developed by the eggs is resumed on the nineteenth day and the increase is very rapid from that time on until the chickens are hatched.

The graph of Fig. 19 is the result of tests with calonimeters.

Staged incubation is usually practiced in the incubator, but not in the hatcher. Usually the incubator is only partially filled at the first set the eggs removed are the hottest eggs and bccause the eggs added to the incubator when the hottest eggs are removed are cool and take in heat instead of giving ofiheat. When the eggs are removed from the incubator and placed in the hatcher, they are usually cooled during the transfer by the lower temperature and humidity hatcher.

of the room'in which the incubator and hatcher are located. This is particularly the case when the eggs are candled for the purpose of removing the infertile eggs and those with dead germs. This candling is usually done at the time of the transfer of the eggs from the incubator to the These eggs, therefore. generally require some reheating in the hatcher after being transferred thereto. The period of reheating in the hatcher after the eggs are transferred to it depends upon the quantity and temperatureof' the entering eggs and trays, and the temperature and humidity conditions in the room and in the hatchet at the time. As the hatching periodprogresses, the quantity of heat. given oil by the eggs and the hatching chicks usually becomes great enough to more than supply the heat required to maintain the desired temperature in the'hatcher. When the temperature exceeds that which is desired'in the hatcher, it

becomes necessary to prevent the eggs and chicks from overheating, and this is done by a cooling medium which reduces the temperature in the hatcher.

Due to these variations in the heat conditions it is necessary to accurately control the temnerature, by cutting off the artificial lim t when necessary and to supply acooling mum as needed.

Inthe embodiment illustrated in the drawings, outside air, as needed, is admitted through a duct it], which extends downwardly from the top ii to the proximity of the fan H, so that the fan M will draw in air through this duct when needed. A damper 20, Figs. 7, l2 and 14, is pivotally mounted on a shaft 2| rotatably supported in basses-22 attachedto the lower ehd of the duct it The hatchet is also'provided with the same damper, although it is not illustrated in Fig. showing' a horizontal section of the hatcher. As before stated, however. the hatcher.

is of the same construction as the incubator and is provided with the same mechanism and operates in the same way as the incubator.

Air is discharged through an opening 23.10- cated so that a part of the air which has passed over the eggs will be exhausted when air is admitt'ed through the duct iii. A damper 24 closes the duct 23, and is pivotaily mounted on a shaft secured in bosses 26 attached to a damper frame 23'.- This damper24 is maintained in a normally closed position by a weight 21, which is secured to the damper by a stem 21". As the dampers 20 and 24 are interconnected, as will be presently pointed out, the weight 21 acts on both of these'dampers.

The dampers 20 and 24 are interconnected by an adjustable connection 28, so that they will open and close simultaneously. This connection 2| is pivotally secured to the upper end of a lever 22 secured to the shaft 2| of the-damper 20. The

side of the rear-wall 2 above the damper opening 23; The lower end of-the-toggle member ll is pivotally attached to anear 3| on the damper 24., Through these connections the dampers 20 and 24 are moved simultaneously. so that both will open at the same time and both will close at the some time.

when the fan I I is in operation, the simultaneous opening of the dampers 20 and 24,'admits outside air through the duct l9, due to the action of the fan, and permits the discharge of air through the duct 22, due to. the action of the fan, without interfering with the normal circula-.

tion of the greater portion of the air within the incubator and hatcher. When there is no neces- .sity for the admission of outside air, both dampers 20 and 24 are closed.

The dampers are opened by an electric motor 35, mounted in a plate-like casting 36 forming a portion of the front wall i, at the forward end of the corridor-B. The operation of this damper motor is under the control of the thermostat M, to open the dampers against the weight 21. The mechanism for opening the dampers 20 and 2d, and maintaining them open when outside air is necessary to be admitted, is attached to the shaft 3?, figs. 12 and 14, of the motor 35. This mechanism is a fiy ball centrifugally afiected device, power being derived'from the action of a pair of oppositely positioned fiy-balls 38, each of which is pivotally connected at the. central portion of a toggle; lever construction having the links 39 and t2. Each link 39 is pivotally se-.

cured to a pair of slotted radially extending ends it attached to the outer end of a sleeve-like member 3H secured to the shaft it? of the motor 35.

The links 32 are each pivotally connected at their outer ends to their respective fly-balls 3d, and at their inner ends to the oppositely positioned, radially extending ends d3 of a cross-head member tit (Figs. 12 and it). This cross-head is secured by a pin to the inner end of a short rod d5 extending rearwardly through a central bore in the outer end of the sleeve member M, in longitudinal alignment. with the shaft 3'17 of the damper motor 35, and is-mounted for reciprocal movement with respectto the sleeve dd in'a longitudinally extending slot 38 in the sleeve 3E.

As the damper motor 35 rotates, the fly-balls 38 move outwardly and, through the toggle links 39 and d2, draw the cross-head M toward the outer end of the sleeve 35,- causing the short end to move rearwardly. The fiy-ball mechanism is preferably enclosed in a housing 4'! which is attached to a hollow boss 48 of the plate 86 in which is mounted the damper motor 35. The short shaft 45 is-loosely supported for reciprocal move ment in'a central opening in the end portion 49 of the housing 61. The -damper mechanism just described, which isoperated by the damper motor 35, opens the dampers-20. and 24 and holds them open, when the motor 35 rotates. When the motor 35 stops,

the weight 2 l'closes the dampers.

The adjustable rod-end, having the rod 5l secured-thereto, is pivoted tojthe lower end '29 i of the lever 29 connected to the air inlet damper 20 by the shaft 2|. A thrust-block 52 is secured to the i'orwar'd end of the rod 5| and in the center of its forward surface is a depression in which is v seated the rear end of the short shaft 45. As the shaft "is 'movedrearwardly, it presses on the causing-the dampers 2B- and 24 to move tozthe open position shown in- Fig. 14. .These dampers are heid in open position as long as the dampermotorli is operated. because-the. fly-.balls are "being continu position. by centrifugal force.

set-screw l4.- The member. is supported for lyrotated and held in their outer.

reciprocal movement in the semi-circular seat of the saddle 55 at the rear of a bracket'56 attached to the housing 41. The button 51 is pro-. vided to indicate whether the dampers 20 and 24 are open or closed. This button is secured to the outer end of the bar 51 projecting through the front wall plate 36. The bar 51' is pivotally secured at its inner end to the upper end of a lever 58 pivoted at 59 on a bracket 60 at the rear end of the housing 41. The lever 58 is notched at its lower end to engage the annular rib 6| on the outer surface of the grease-retaining member 53. The button 51 is moved forwardly and rear-' wardly as the dampers 20 and 24 are opened and closed. The position of the button 51 in Fig. 12 indicates that the dampers 20 and 24 are closed, while the position of this button in Fig. 14 indicates that these dampers are open.

Figs. 3, 4, and 6 diagrammatically illustrate the devices for controlling the temperature. thermostat I8 is employed for controlling the circuit for the heater and the circuit for the damper motor 35 for operating the dampers 28 and 24. This thermostat controls the temperature within predetermined limits whether the air is subjected to artificial heat or to cooling air. This thermostat acts through two different ranges of temperature whose midway or average point is the same. The operation of this thermostat and its connections will be more fully described later.

The thermostat I8 has four'contacts which are preferably permanently located at the factory so that they cannot be changed by the user. These contacts are numbered 62, 63, 84, 85. The contact 82 is located so that it will be engaged by the column of mercury in the thermostat I8 at 97.5 F., the contact 63 at 97 F., the contact 813 at 965 F. and the contact 65 is located at any convenient location below the contact 55. These temperatures are selected for purposes of illustration and may be varied, preferably at the factory, to meet various conditions, but the temperatures indicated are generally used. The contacts 82, 63, 64 and 65 have the short leads t6, 6?, 88 and 59, respectively connected thereto. The lead 68 is secured to the terminal 79 by the screw TI. The lead 67 is secured to the terminal 72 by the screw 73. The lead 98 is secured to the terminal 19 by the screw '55 and the lead 69 is secured to the terminal it by the screw IT. The terminals ill, 12, i9, and F6 are mounted on one side of a block ?8. By removing the screws H, I3, 'Ii'aand Tl the short leads 58, El; 88 and 89 can be disconnected from their terminals on the block 78, so that the thermostat 58 can be removed from its casing for purposes of renewal or for any other purpose. to the terminals I8, 72, i i and I8, respectively by the screws 83, 8d, 95 and 88 extending through the block it from the opposite side thereof.

The lead '29 secured to the terminal I8, is' connected to the line El and through the resistor 88 to the line 89 and to solenoid 90. Power lines 9| and 92 are provided, in which is a two-pole switch 93, 93 The line 89 is connected through the condenser 94 to the power line 9!. The core 95 of the solenoid 9t carries the switches I8, 88 IS The lead 80, secured to the terminal 12, is connected, through a resistor 96, line 91, and a con- 7 denser 98, to the power line 9I and is also connected, through resistor 96, to the winding of the solenoid 99. The windings of both solenoids are connected to a line I00, which extends to a line The Other leads l9, 88,'8I and 82 are connected' IOI connecting the fan II to the power line 92, the fan being also connected by a line I02 to the power line 9I. The fan II is always supplied with current, when the two pole switch 93, 93, is closed, so that there will always be a circulation of air when current is supplied through the power lines 9|, 92.

The lead 8|, secured to the terminal 14, is connected to a line I03. The lead 82, secured to the terminal I6, is connected to the line IOI by a line I 04. The switch I8 and the lines 81 and I03 form an electrical interlock.

The core I05 of the solenoid 99 carries the switcheslll and I8. The switches I8 and I8 are provided to open and close a heater circuit which extends from the-power line 9|, through a line I00, a heater I6 having a pilot light I0'I in the line I01, a line I09 having gaps for the switches I8 and I8- and the fan line ml to the power line 92.

The switches I8 and I8 close gaps in the power line 92 which connects to one side of the damper motor when the switch H0 is closed.

A humidifier II I in a line H2, H3, is provided to supply the necessary humidity to the air circulated bythe fan II. There is a pilot light II 4 in the humidifier circuit to indicate when the humidifier is operating. A humidostat I I5 controls-the operation of the humidifier in accordance with the humidity of the air. When the moisture content of the air is less than that ,required, the humidostat H5 closes the line II2, H3 and then additional moisture is supplied to the air by the humidifier III. When the moisture content of the air becomes sufficient, the humidostat H5 opens the'line H2, H3 and the humidifier becomes inoperative.

Figs. 3, 4, 5, 6 show the various positions of the switches I8 I8 58, I8 and 3. Fig. 3 shows the switches I8 and I8 closed, at which time the heater circuit I09, I08 is closed. The switch I8 bridges the gap between terminals H8, H6 and the switch I8 bridges the gap between terminals II'I, Ill. In this position of the switches I8 and I8, the heater circuit I89, I98 is closed and artificial heat is supplied by the heater I6. The damper motor circuit is open at this time because the gaps in the lines 92 and 87 and I03 are not closed by the switches i8 I8 and I8 The heater I8 will continue to supply artificialheat until the temperature reaches a predetermined degree, 97 in this case, when the thermostat IB, due to the column of mercury reaching the contact 83, will act to de-energize the solenoid 99. The switch I 8 will move away from the terminals H5, H5, resulting in breaking the heating element circuit. When this occurs the switch I8 will move to the position shown in Fig. 5, which shows the switches I 8 and i8? open. In this position the switch I8 will bridge the gap between'terminals H8, I I8, in the power line 92. At this time both the heater circuit 509 and the damper motor circuit are open; Consequently no artificial heat is being supplied and no outside air is being admitted and no inside air is being discharged.

The switches I8 l8, l8, Hi I8 will remain in the position indicated in Fig. 5 until the temperature rises to a predetermined degree or drops to a predetermined degree.- If the temperature drops to a predetermined degree, 9'7? Fiminus, or about 969 F., in this case, the thermostat I8, because the column of mercury opens the circuit at contact 63,- will act to cause the switch I8 to engage the terminals II6, I I6, when but cooling air being admitted and inside air discharged through dampers and 24. when the temperature has dropped to 96.9 F., the switches are in the positions indicated in Fig. 6, when both the heater circuit and damper motor circuit are open and no artificial heat is being supplied nor air being admitted or discharged. At this timeswitch I6 engages the terminals H6, H6 in the heater circuitand the switch I9 engages the terminal II9, I I9 in the damper motor circuit, while the switch I8 engages the terminals I20, I20 in the interlock circuit. Upon increase of the temperature to 97 F. the mercury column. reaches contact 63, and the switches again take the positions indicated in Fig'. 4, thus causing dampers 20 and 24 to open.

Diagrammatic Fig. 11 also shows that the thermostat I8 is fixed to open the switch I9 at 97 by moving it away from the terminals II6, I I6 in the heater circuit, and to close it at appoximately- 969 F. Fig. 11 also shows that the thermostat I8 is fixed to move the switch li k away from the terminals III, III, in the heater circuit and the switch I8 into engagement with the terminals H9, H9 in the damper motor cir-- cuit and the switch 16 into engagement with the terminals I20, I20 in the interlock circuit, at 97.5" F., so as.to close the damper motor circuit. From that time on the temperature is controlled by opening at 97 F., and closing at 969 F., the

at this time. litter the temperature drops to 96.5 F., the temperature is controlled by supplying artificial heat and cutting 011' this heat until the temperature rises to 975 F., when the temperature is again controlled by opening and closing the dampers 20, 24.

When eggs are placed in the hatcher, the temperature drops and artificial heat is supplied until the temperature reaches 97 F., when itris cut oil. When the temperature drops to 96.9 F., artificial heat is again supplied. During this interval, the structure is closed and no outside air is admitted. When the eggs are removed from the incubator to the hatcher, they are cooled by the outside air and the temperature in the hatchet is reduced due to the opening of the hatcher door. When chicks which have hatched are removed from the hatcher, the temperature in the hatcher is reduced, for which reason it is necessary to supply artificial heat in the hatcher also. Artificial heat is also required in the hatcher for preheating the empty machine beiore eggs are placed therein, and for maintaining the proper temperature when the number of eggs transferred thereto is small or the room temperature is abnormally low. The temperature is controlled in the hatcher by the same kind of means used for that purpose in the incubator.

When the temperature rises to 975 F., the control is through the admission and discharge of air. This continues until the temperature drops to 96.9 F.,-when the admission and discharge of air is discontinued until the temperature rises to 97 F. when air is again admitted and discharged.

' each of contacts 62, 69 and 64.

' As above described, the switch blades 93 and v 99* are connected to opposite sides of the electric switch blade, as 93*, to the other switch blade,

as 99, because the details of connection oi one switch blade to one side of the power source, and of the other, switch blade to the other side of the power source are of no importance to the operation of the switches of the relay and their control by the thermostat I8.

In order to simplify and clarify the description of the circuits illustrated in these figures, the thermostat contact 62 will be considered. as directly connected to resistor 69 .andalso wire 91; the contact 69 will be considered as directly connected to the resistor 96; the contact 64 will be considered as connected directly to wire I03; and the contact 66 will be considered as directly connected to the wire I04.

In Figure 3, the parts arepshown in the position taken when the temperature is below 96.5 degrees F., wherein the mercury of thermostat II will be below the contact 64. -A circuit will then extend from switch blade 99 -to wire IOI, through'wire I00, through solenoid 99, thence through condenser 96 to switch blade 93;.1ikewise, a second circuit in parallel with this circuit will extend from wire I00, solenoid 90 and condenser 94 to switch blade 93. The solenoids 99 and 90 will be fully energized to engage switch Il'with contacts H6 and switch I 8 with contacts II'I, respectively. This will complete a circult extending from switch blade 93 through a portion of wirefIOI, II6, I9 H6, H1, I9, III, wire I09, heating element I6 (also line I01 and pilot light I01 in parallel with element I6), wire I06 to switch blade 93., Due to the mercury level of thermostat I0, the contact is isolated from The heater I6 is then voperative,'the damper motor 36 is inoperative and the fan I I is operative.

Until the temperature has risen (due to operation of the heater) to a value above 97 degrees F. and below. 97.5 degrees F., the position of Figure 3 will be maintained due .to the factthat, when the mercury, in rising, engages contact 64, current can then how no further through. wire I03 than I20 due to the upward position of 1 switch I6 and the solenoid cannot then be weakened by shunting for that reason. Thus, when the temperature has risen above 97 degrees F., the mercury completes a circuit between contacts 69 and, to bring the parts to the posi- 1 tion shown in Figure 5.

As shown in Figure 5, completion, by the thermostat mercury, of a circuit between contacts 66 and 63, causes resistor 96 to operate as a portion of a shunt to weaken the solenoid 9'9 and permit the switch III to be removed from contacts H6, H6. A circuit then extends from switchblade 93" through wires IOI,- I04, contact 66, the mercury, contact 63, resistor 96, condenser 99 to switch blade 93. Due to the fact that the re- I sistance value oi solenoid 99 is much greater than that of resistor 96, a much weaker circuit extends from wire IOI through solenoid 99 to condenser 99 and thence to switch blade 99, which weaker circuit is in parallel with the above de- 1 scribed circuit including the resistor 96. A circuit also extends from switch blade 93- through a portion of wire "I and wire I00, through solehold 96, condenser 94 and thence to switch blade 93. This circuit of lumcient strength to fully I energize solenoid 90 to maintainswitch I9" in engagement with contacts III, III. Due to the position taken by switches I3 and I9, the. energ'izing circuit for the heating element I0, which was complete in Figure 3, isnow open and the are operative when the incubator, and/or hatcher,

is p r ting on heat control. when sunicient heat is generated in the eggsto'rai'se the tem-. perature above 97.5 degrees F., the parts will take ,the position shown in-Flgure 4 to accomplish a change-over, in the incubator and/or hatcher,

from heat control to air control,

m Figure 4, a circuit extends from switch blade '93, through wire Ii, wire I00, to'contact 95 and thence, in one direction, through contact 93, resistor 99, and condenser 93, to switch blade 93, and, in the other direction, from contact 65, through contact. 62,; resistor 93, condenser-94 to switch blade 93. These circuits operate-as shunting circuits toweaken' energ'lzation-of solenoids 99 and 90, which energization is accomplished by circuit branches extending fromwireIOI oi the above circuit, through wire I00, through solenoid .99 to condenser and thence to switch blade 93, and from wire I00 through solenoid 90 to condenser 94 and thence to switch blade 93. At';

the same time, the mercury will complete a branch circuit between contact 95 and contact 34, which extends i'romcontact 90 through wire I 03 to contact I20, through switch 18, contact I20 and wire 91 to resistor 83. The solenoids 99 and 90 will be so far weakened as to permit withdrawal of switch I9 i'rom contacts I I9, I I6, and switch I8= from contacts -III, III, and permit engagement oi switch ll with contacts II8, II 3 and engagement 01' I 9 with contacts III, 9, as well as engagement 'of switch I9 with contacts I20, I20, to complete the abovedescribed branch circuit from contact 99 through contact 04 and switch blade I9 to resistor 89.

The position of the switches is such as to maintain the heater energizing circuit open, while at the same time closing the damper motor energlzing circuit, which circuit extends as follows: switch blade 93-, H0, H9, I9 Il9,-il0, damper motor-30 to switch blade 93. In this position of parts, the fan is operative, the heating element I6 is de-energized and the damper motor 35 is operative. This position of parts is maintained until thetemperature, due'to introduction of cool air, has dropped to a value above 96.5 degrees F. and below 97 degrees F. When the mercury is falling, prevention of restoration of the full energization of solenoid 90 upon disengagement ot-the mercury from contact 62 is prevented 94 to switch blade 93 takes the place of the circuit from contact 65, through the mercury, contact 63, resistor 98, condenser 90- to switch blade 93. Thus, the de-energization of the solenoid 90 is maintained to prevent it from operating to withdraw switch I35 from contacts 9, I I9, and

'switch I9 from contacts I20, I the temperature has fallen sufliciently to cause restoration of the full energization of solenoid 99, when the mercury takes the position of Figure 6, where the temperature last a value 'above 96.5 degrees F. and below 97 degrees F.

In the position of Figure 6, the solenoid 99 becomes sufliciently energized when the mercury falls below the contact 63. In that position of parts, a circuit extends from switch blade 93! through wire I M, a portion oi wire I00, solenoid 99 and condenser 90 to switch blade 93 to fully energize solenoid 99 and withdraw switch blade I8 from engagement with contacts 9, II8.

A circuit for shunting and maintaining the solenoid 90 weakened extends from switch blade 93*, through wire IN, wire I04, contact 65, the mercury, contact 94, wire' I03, contact I20, switch I9, contact I20, wire 81, resistor 99, and condenser 94, to switch blade 93. A weak circuit:

extends from wire I00, solenoid 90, condenser 96, to switch blade 93, The solenoid 90 is thus maintained suiliciently weak to retain its switch in the position of Figure 4, so that the switch I9 engages contacts I20. The position of the switches is then such as to maintain [the heater energizing circuit and the damper motor energizing circuit open so that the heater I6 and Control will be accomplishedby shunting the,

coils 90 and/or 99 with resistances 98 and/or 96 of proper value to destroy the resonance of the circuit through the-coils 90 and/or 99 to achieve the same manner of operation as is described above. I The operation 01 the fan II is undisturbed by the operation 01 the switches through the thermostat I8 and .at any time'the damper motor may be de-energized by manually opening the switch IIO. I

Likewise, the connection of the humidifier Iii, through manual switch I II and wire I I3 with the switch blade 93' and: through wire .I I2 with the switch blade 93, permits oi this operation selectively, totally independently of the thermostat I8.

The supply of artificial heat and the admission of outside air and discharge of inside air are controlled the same in the incubator as in the hatcher.

The method of incubating and hatching eggs will be understood from the foregoing description, one means for practicing which is illustrated in the accompanying drawings. The eggs are placed in the incubator, artificial heat is supplied when needed, cooling air'is admitted and hot air discharged when the temperature in the incubator is too high, the eggs are transferred from the incubator to the hatcherafter they develop heat, and the supply of artificial heat and-admission and. the" discharge of air is controlled thermostatically. While the means ior practicing the method utilizes cooling air for reducing the temperature, any means'may be employed which willlower the temperature to the desired degree.

My invention also embodies the method of controlling the, temperature by supplying artificial heat when needed, admitting outside air and discharging inside air when necessary, and controlling the supplying of artificial heat and admission and discharge'of air by a single thermostat.

My invention also embodies the method of controlling the supplying of artificial heat and the admission and discharge of air in an incubator and a hatcher by a single thermostat in each.

The thermostat I8 is removably mounted in a support attached to a removable portion of the incubator or hatcher. A bracket I2I, having a vertical plate like member I2I with two horizontal projections I2I and HI, is attached, by a portion I2I to a removable portion I22, such as an instrument board, of the incubator and hatcher (Figs. 8 and 20). This bracket supports a casing consisting of two parts I23, and I24, secured together by screws or rivets I25, the casing being secured to the bracket I2I by screws such as that shown at I26. A cup I21, secured in the casing I2I by a screw I28, holds a rubber or other yielding seat I29 for the thermostat I8. Near the upper end of the thermostat I8 is a clamp I30 pivoted at I3I to a plate I32 projecting from the vertical portion I2I of the bracket I2 I. This plate has a semi-circular opening I33, which, with the inner wall I34 of the clamp I30, forms a circular opening to receive a rubber or yielding sleeve I35 with an opening I36 therein through which passes the upper portion of the thermostat I8.

The leads I9, 80, 8|, 82 have terminals I31, I38, I39, I40, respectively, which are inserted into sockets to connect the thermostat to the windings 90 and 99 and to the interlock circuit I03 and the line 92.

The thermostat I8 'can be removed from the incubator or hatcher by removing the parts I23, I24, swinging the clamp I30 on its pivot to release the rubber sleeve I35 and disconnecting the leads 66, 61, 68, 69 from the plate I8. The thermostat is then free to be lifted out of the resilient seat I29.

The use of a single thermostat permanently set at the factory for. certain temperatures, greatly simplifies the control of the-temperature'in the enclosure. Regulation of the thermostat by the operator to keep the controls in the proper relation is eliminated. With the previous system it required from one to four hours to make the necessary adjustments of the thermostats before setting eggs. The new thermostat is factory calibrated, and all the operator has to do to place the apparatus in full operation is to close the main switch. This thermostat could be provided with adjustable contactsif occasion should require an adjustable thermostat to meet the requirements of different locations or different operating conditions.

When the thermostat is permanently set at the factory, the danger of failure in hatching, due to improper adjustments by inexperienced operators, is eliminated. 1

The use of a single thermostat also eliminates the possibility of crossing the controls, which is done sometimes when two thermostats are employed, for the same'structure, due to Stratification of the air causing a momentary difference in temperature at two control points.

The single thermostat is more sensitive and results in a more accurate control of the temper-.

ature. This results in a greater conservation of moisture and the saving of power because it is not necessary to admit cooling air for as long periods as before. This reduces the time during It will also be understood that the incubator and hatcher will have independent thermostatic controls so that different ranges of temperautre can be maintained in the incubator and hatcher if desired. In the caseof combination machines,

where incubating and hatching are both carried out in one structure, one thermostatic control would sufiice for both incubating and hatching.

While the inventionhas been illustrated and described with reference to an incubator and hatcher, it is to be understood that it involves a control system for maintaining a uniform condition and in which an element, movable in response to changes in condition, selects a device for eifecting the condition in opposite extreme positions and controls the application of the selected device in an intermediate position. Although more speciflcally adapted for temperature regulation, it is clear that the control is applicable as well to maintaining other uniform conditions. While electric circuits provide a simple means for applying the control, it is to be understood that the invention comprehends othermeans to select and apply the condition-effecting devices.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a temperature regulator for an enclosed structure adapted to be affected by animal heat generated therein, a source of artificial heat, a source of cooling air, a single thermostat operable within a given range of temperature to independently control either the artificial heat or the air and operable over a greater range of temperature to transfer the control of said thermostat from heat to air and vice versa.

2. In a. temperature regulator for an enclosed structure, a source of artificial heat, a source offresh air, a single thermostat operable within a. given range of temperature to independently control either the artificial'heat or the air, said thermostat being operable at a higher temperature to transfer the control of said thermostat from the heat to the air andoperable at a lower temperature to transfer the control of said thermostat from the air to the heat.

3. In a temperature regulator for an enclosed structure, artificial heating means, means to cut in and cut out the artificial heating means to maintain a given range of temperature in the structure, means to admit outside cold air to reduce the animal heat-therein when that heat rises above the point at which the artificial means is cut out and maintain the temperature within said range, a single thermostat adapted to select either heating or cold air control of said temperature and to control the application of whichever is selected so as to maintain the temperature within said range, and means for causing the and cutting off the source of artificial heat, an

, cutting off the cooling means, a thermostat responsive to the temperature within the enclosure and having a moving element adapted tocause the opening and closing of either of said firstmentioned or said second-mentioned circuits in the same predetermined temperature range and adapted at extreme temperatures beyond said range to select the circuit to be controlled in said range.

5. In a temperature regulator for an enclosed structure, a source of artificial heat, a source of cooling air, means for applying and cutting oil? the source of artificial heat and the source of cooling air, an electric circuit tor .said means for applying and cutting ofi the source of arti ficial heat, an electric circuit for the means for applying and cutting oil the source of cooling air, and a thermostat responsive to the temperature within the enclosure and having a moving element adapted to-cause the opening of the first named circuit when said temperature rises to a predetermined degree, to cause the closing of said first named circuit when said temperature drops to a predetermined degree, to close the circuit for the source of cooling air when said temperature rises to a predetermined degree and thereafter cause the opening and closing of the circuit for the source of cooling air within the same range in which the source of artificial heat is controlled.

6. In a control system, an element movable in response to a condition to be controlled, oppositely acting devices for affecting said condition, spaced elements cooperating with said first-mentioned element in its opposite extreme positions for selecting the proper device to control said condition, and at least one intermediate element cooperating with said first-mentioned element in an intermediate position to control the application of said selected device.

7. In a control system, an element movable in response to a condition to be controlled, oppositely acting devices for aifecting said condition, at least one element adapted to cooperate with said movable element to independently control either of said devices, an element located on one side of said at least one element and cooperating with said movable element to select one of said devices to be controlled by said at least one element, and an-element located on the opposite side of said at least one element and cooperating with said movable element to select the other or said devices to be controlled by said at least one element.

8. In a control system, anelement movable in response tov a condition to be controlled, a plurality of elements adapted to be successively engaged thereby, and a plurality of devices adapted to restore said condition, said devices having an opposite effect on said condition, certain of said plurality of elements selecting, in. response to movement of said first-mentioned element, the proper device to control said condition and at least one of said plurality of elements being located intermediate said certain elements controlling the application of the selected device in response to movement of said first-mentioned element.

9. In a control system, an element-movable in response to a condition to be controlled, and at least three elements adapted to be successively engaged by said first-mentioned element, oppo-l' sitely acting devices forafiecting said condition, the extreme elements of said atleast three elementsselecting the device to be operated to re-' store said condition and at least one intermediate element of said at least three elements controlling the operation of said selected device.

10. In a thermostatic control system, an element movable in response to change in tempera-,

ture, heating means and cooling means adapted to be independently applied to secure a desired temperature condition, an element cooperating with said movable element in a high temperature position thereof to select said cooling means for operation, an element cooperating with said movment movable in response to change in tempera-' ture, heating means and cooling means adapted to be independently applied to secure a desired temperature condition, and at least three elements adapted to be successively engaged by said first-mentioned element, an extreme element of said at least three elements selecting the cooling means for operation, the opposite extreme element of said at least three elements selecting the heating means for operation, and at least one intermediate element of said at least three elements controlling the application of the selected means. a

12. In a thermostatic control system, a contact element movable in response to change in temperature, heating means and cooling means adapted to be independently applied to secure a desired temperature condition, a contact cooperating with said movable element in a high temperature position to select said cooling means for operation, a contact cooperating with said movable element in a low temperature position to select said heating means for operation, and at least one intermediate contact cooperating with said movable element in an intermediate temperature position to control the application of the selected means.

13. In a thermostatic control system, a contact element movable in response to change in temperature, at least three contacts adapted to be successively engaged by said contact element, electric circuits for said contacts and contact element, .heating means and cooling means controlled by said circuits, one extreme contact selecting the cooling means for operation, the oppoingmeans and cooling means controlled by said circuits, the last engaged contact in movement of said element in said one direction selecting one of said-means. for operation, the last disengaged contact in movement of said element in the opposite direction selecting the other means for operation, and at least one intermediate contact en- 7 gaged and disengaged by said element to control the application of the selected means to secure the desired temperature condition.

15. In a thermostatic control system, a contact element movable in opposite directions in response to increase and decrease in temperature, at least three contacts progressively engaged and disengaged by said element in movement in opposite directions, circuits for said contacts and element, and heating means and cooling means controlled by said circuits, at least one intermediate contact of said' contacts cooperating with the ,movable element to independently control either the heating or cooling means, and other of said contacts being engaged and disengaged at higher and lower temperatures by said element to transfer the control from one of said means to the other as required by the temperature condition of the medium acted upon.

16. In a thermostatic control systems, mercury column expansible and contractible upon increase and decrease in temperature, a plurality of spaced terminals adapted to contact with said column in difierent positions thereof, circuits connected to said terminals, and heating and cooling means controlled by said circuits, the lowest of said terminals connecting said column in the circuits, the next higher terminal constituting a lower changeover point and serving to select said heat ing means for operation when disengaged by said column, the uppermost of said terminals constituting an upper change-over point and serving to select said cooling means for operation when engaged by said column and at least one of said terminals located intermediate said points adjacent the temperature point to be maintained and controlling the application of themeans selected. I

17. In a thermostatic control system, a contact element movable in opposite directions in response to increase and decrease in temperature, a plurality of contacts progressively engaged and disengaged by movement of said element in opposite directions, heating means, cooling means, and two double throw rel'ays for controlling said means, the relay terminals in one direction bein serial connected with one of said means and in. the opposite direction with the other of" said means, said element cooperating with the extreme contacts to cause movement of one of said relays in opposite directions to select the means to be applied, said element cooperating with at least one intermediate contact to cause movement of the other relay in opposite directions to control the application of the selected means.

18. In a thermostatic control system, a. contact element movable in opposite directions in response to increase and decrease in temperature, at least three contacts progressively engaged and disengaged by movement of said element in opposite directions, a power circuit, heating means, cooling means, a pair of double throw relays having their contacts in one direction connected in series with one of said means and the power circuit and their contacts in the reverse direction connected in series with the other of said means and the power circuit, operating coils for said relays, means connecting one end of said coils together and to one side of a control circuit, the opposite ends of said coils being connected through condensers to the opposite side of said control circuit, means connecting said Joined end of said coils to said element, and an interlock switch closed when one of said relays is de-energized, the first of said contacts being connected to one side of said interlock, the second vto cause said cooling air to be applied.

of said contacts being connected through a resistor to the oppositeend of the coil of the other of said relays, the third of said contacts being connected to the other side of said interlock and through a resistor to the opposite end of said one 6 relay, said resistors being of a value to by-pass the coils sufiiciently to de-energize the relays.

19. In a temperature regulator for an enclosed structure, an electric heater, a source of cool-' ing air including adamper, a motor for operating 10 said damper, independent electric circuits for said heater and said motor, and a' thermostat operable within a predetermined range of temperature to independently select and control either of said circuitsand operable at certain temperatures to select and control the circuit to be employed to maintain the temperature within said range.

20. In a temperature regulator for an enclosed structure, a source of heat,'a source of cooling air, means for'applying and cutting oft the source of heat,'means for applying and cutting off the source of cooling air, an electrical circuit for each of said means, means for opening and closing said circuits, a single thermostatic means for selectat ing the proper circuit. to be controlled for control of the temperature within said structure and for controlling independently whichever circuit is selected in accordance with the temperature within the structure within the same identical temperature limits, and electrical interlock means adapted to maintain air control of said temperature once air control is established even though said temperature drops to a point where-normally heat control would be restored.

21. In a temperature regulator for an enclosed structure, a source of heat, a source of cooling air, means for applying and cutting ofi the source of heat, means for applying and cutting off the source of cooling air, an electrical circuit for each of said means, means for opening and closing said circuits, a single thermostatic means for selecting the proper circuit to be controlled and for controlling independently whichever circuit is selected, with the temperature within the structure within the same identical temperature limits, and electrical interlock means adapted to allow said temperature to be controlled by said cooling air within the same limits as by said heat.

22. In a temperature regulator for an enclosure adapted to be afiected by natural heat generated therein, a source of artificialheat, a source of cooling air, and means adapted to maintain the temperature within said enclosure within predetermined limits comprising a single thermostat responsive to said temperature, two relays which when subjected to an electric current cause said heat to be appl ed, a control adapted to be engaged by said thermostat at the upper of said limits to so actuate one of said relays as to cause said heat to be cut ofi, and a second contact beyond said first contact adapted to be engaged by said thermostat at a higher predetermined temperature to so actuate the other of said relays as 23. 7 In a temperature regulator for an enclosure adapted to be affected by natural heat generated therein, a source of artificial heat, a source of cooling air, and means adapted to maintain the temperature within said enclosure within predetermined limits comprising a. single thermostat responsive to said temperature, two relays which when subjected to an electric current cause said heat to be applied, a-contact adapted to be engaged by said thermostat at the upper of said 76 limits to'so actuate one of said relays-as to cause said heat to be cut oil. a second contact beyond said first contact adapted to be ensas dby said thermostat at a higher predetermined temperatureto so actuate th'e other of said relays asto' cause said cooling air tcbe applied, a third contact ahead of said two contacts adapted to be ensased by said thermostat at a lower predetermined temperature. and an interlock circuit established thereby and by said second relay-and adapted to maintain said second relay in the relationship in which it is actuated by the engagement of said thermostat with said second contact. whereby said cooling air is applied and controlled to maintain said temperature within said'limits and the heat control is restored when said temperature drops to such an extent as to cause said thirdm contact to be disengaged by said thermocannascmm 

